> ## Documentation Index
> Fetch the complete documentation index at: https://primer.io/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# showUniversalCheckout

```ts TS theme={"dark"}
showUniversalCheckout(
    clientToken: string
): Promise<Void>
```

Showing Drop-in Checkout is the simplest way to integrate with Primer. With just a few lines of code, you can display a fully in-context checkout UI with all your payment methods.

Using Drop-In Checkout is as easy as implementing one line of code.

```ts TS theme={"dark"}
import { Primer } from "@primer-io/react-native";

Primer.showUniversalCheckout(clientToken);
```

Note that there are more options which can be passed to Drop-In Checkout.
Please refer to the [Configure call documentation](/sdk/react-native/v2.x.x/primer/methods/configure).

## Parameters

<Expandable title="Parameters" defaultOpen>
  <ResponseField name="clientToken" type="string" required>
    A string containing a client token as returned by the Primer API when you
    [create a client session](/checkout/client-session#create-a-client-session).
  </ResponseField>
</Expandable>